Modern user interfaces in complex systems often include indicators of failure states or other conditions that require user interaction, or that impart otherwise important information. In a well-designed system, such indicators may appear before user interaction is critical, allowing a user time to assess a situation and determine a course of action. Because indicators may not require immediate action, they are often designed to be minimally intrusive so that a user may continue to operate the system. Unobtrusive indicators may allow a user to continue operations, but a user may also ignore such indicators, or even fail to see them.
A system may address this problem by demanding a user acknowledgment of a particular indicator. Such acknowledgement diverts the user's attention from operating the system and requires some type of interaction. Where a user is performing a complex task, such as flying a jet, any diversion of the user's attention is undesirable.
Consequently, it would be advantageous if a method and apparatus existed that were suitable for acknowledging a user has observed an indicator without diverting the user's attention or demanding a physical interaction.